Method of forming structural glass



May 7, 1946. F. w. PRESTON 2,399,825

METHOD OF FORMING STRUCTURAL GLASS Original Filed March 7, 1942 3Sheets-Sheet l F. W. PRESTON METHOD OF FORMING STRUCTURAL GLASS May 7,1946.

3 Sheets-Sheet 3 Original Filed March 7, 1942 glass through friction ordrag" by any of the track 24 that is secured to the underside of thePatented May 7, 1 946 UNITED STATES PATENT OFFICE 2,399,825 METHOD OFFORMING STRUCTURAL GLASS Frank W. Preston, Butler, Pa.

Original application March 7; 1942, Serial No. 433,798, now Patent No.2,342,218, February 22, 1944. Divided and this application March 19.1943, Serial No. 479,690

12 Claims. ((11. 49-84) My invention relates to the forming ofstructural shapes and the like from sheet glass or other plasticmaterials, and is a, division from my application, Serial No.'433,798,filed March 7, 1942 (now Patent 2,342,218,).

One object of my invention is to provide a structural form of glasswhich may have a reinforcing mesh of wire after the manner of wiremeshes with a gear wheel 29 that drives a gear glass, or with thereinforcement omitted therewheel 3|. The gear wheels 21, 29, 29 and 3|are from, which is better suited for use as a window all journaled in ahousing 32 which is partly or light-transmitting closure in a wall orroof broken away in Fig. 3. Ashaft 33 is journaled in than are variousforms of glass panels or the bearings 30 that are adjustably mounted onlike heretofore employed, and which is of greater rocker arms orbrackets 34 that are respectively strength than various other forms ofglass panels pivotally supported by the shaft 35 of the gear such as thecommon corrugated glass. wheel 3! and a shaft 36 on a standard 31. The

Another object of my invention is to provide shaft 33 carries a gearwheel 38 and a crimping a method of forming a flat sheet of glass to aroll 39. uc u l p y bending Operations. W e Therocker arms 34 carryrollers 4| that ride maintaining a uniform thickness f th glass on camtracks or trangs 42 that are afilxed to h gh ll portions of the shape,and withthe cradle 9, so that as the cradle is moved by out disto t onof y su f ce portions of the the rack and pinion, the crimping roll willbe raised and lowered in an arc around the shafts 35 and 36 as an axis,the radius of movement being such that driving engagement is maintainedbetween the gear wheels 3| and 38.

The table II has depressed andraised areas extending transverselythereof to which a hot 26, to bias the casing in a counter-clockwisedirection andlthus yieldably hold the roller 23, against the cam track24.

5 The shaft 22 carries at its ou'ter'end a pinion 2'! that engages agear 28, for picking up oil from a, pool and Oilingthe pinion 27. Thepinion 2T shaping implements.

In the accompanying drawings, Figure 1 is a plan view of apparatus forpracticing my invention; Fig. 2 is a view thereof partly in endelevation and partly in section; Fig. 3 is a view of the apparatuspartly in side elevation and partly glass sheet is shaped to form thecreme] and in section; Fig. 4 is a planviewof a portio of merlonportions 44 and 45, respectively, (Fig. 5). the apparatus of 3; 5 15 anedge The roll 39 has three rib-like crenel-forming on an enlarged scaleof structmfal glass portions 46 that extend lengthwisethereof in memformed by the machmeand 6 is a order to depress the glass into therecesses 41 gratic view, used for the purpose of explainin the table Theribs are each of greater gsggg g r r g g igfi' for base, radialdimension than the depth of the crenel o e members i having slidewaysformed therein for gig gf g 31 3 il zg g igg g gg g gi sndably Supportmgtunnels 3 cradle 9 that the depressions. The table II is longitudinallyg jf z g gg g f under surface and adjustable on the table 9, by screws48 and 4s,

A reversible electric motor I2 is employed to p respect to the cnmpmgIon and we cam move the cradle back and forth on the slidemus 7 Ways,and to drive a crimping Tenet Themotm. The experience of the industry inmaking corl mtes through reduction gearing in a box |3' rugated glasshas been that there'is no true or to drive a gear wheel [4 which mesheswith a accurate rolling, because of the different angugear wheel i5 thatdrives a gear wheel I6 which 4. lar Speeds of those portions of the c ss m h t th rack is rollers that engage the glass. Consequently The gearwheel I5 is secured to a shaft [1 of there is scuffing and man'mg of hglasss diflerential gear ,wheel 20. The differential It will beobviousthatif y table H a d c d e earing has a casing I 8 that carries thepinions 9 e driven a constant Speed during the C o i3 and isoscillatable by means to be described. 5( lating process, then in theabsence of any dif- I'he other differential gear Wheel 2| is ountedferential mechanisms, the roller 39 would rotate on a shaft 22. Thecasing l8 has an extension at uniform angular speed, and since if itspethat carries a roller 23 which engages a cam riphery is fluted, andvarious parts'of said surface lie at very different distances from itsaxis,

cradle 9. Another extension 25 of the casing the peripheral speeds ofthese surface areas I8 is yieldably urged downwardly by a Spring 2 wouldbe different, and some of them couldnot synchronizewith the linear speedof the table.

As the motor is operated to move the cradle 9 and table II from thepositionof'Fig. 3 toward and past that shown in Fig. 1, the cam" rails42 cause raising and lowering of the roll 39 and its gear wheel 38, sothat the ribs 46 will press the glass snugly into the corners of thetroughs or crenels. Reference to Fig. 6 will indicate the necessity forthis raising and lowering of the roll. As shown, the width of thecrenels -3 and F-G is the same as the width of the merlons D-E. When therelative traveling movement of the roll and the table brings the rollcenter 0 directly above the point E. the corner I of the rib 46 mustenter the corner at F to press the glass therein. This result could notbe attained if there were a pure rolling movement of the rib 46 on thesloping surface of the table at E-F after the manner in which gear teethfunction. In the case of gear teeth, clearance is provided at theirroots and tops, to permit of pure rolling movement. I desire to avoidsuch clearance (except for glass thickness), so as to pin the glasssnugly into the crenel corners at F and G, and to do so withoutscufling. To accomplish this, I make the surfaces at E-F, K-J and GHstraight, and roll the glass on the surface D-E, on radius 0-]?! (r-1)and then immediately transfer the rolling action to surfaces J-I andG-F, with the radius OF (1-2). Since the distance OF is greate tran OEthe center 0 of the roll must be caused to rise as above explained, whenthe rolling action is transferred from the inerlon areas to thecrenel-forming areas.

This raising and lowering of the rocker arms 34 causes the gear wheel 38to tend to roll on the gear wheel 31, thus giving a certain differentialspeed to the gear wheel and the ro 1ler.'

results in asynchro- This differential movement nous speeds as betweenthe table H and roll 39. In order t0.compensate for these variablespeeds of the roll and to synchronize rolling or angular speeds or thecrenel and merlon-forming areas of the roll, with table speed, the camtrack 24 is employed. This track is so contoured that each time therails 42 raise the roll 39, the cam track 24 will rock the differentialhousing l8 slightly in a counterclockwise direction, to thereby temporarily reduce the speed of the shaft 22 and hence that of the gearwheel 3|, as when rolling the crenel at F-G. The cam track 24 has itscamming surfaces so proportioned that such reduction in speed of thegear wheel 3| also compensates for the slight temporary change in speedof the gear wheel 38 and the roll 39 relative to the gear wheel 3|,during such raising movement Similarly, when the cam rail 42 lower theroll 39, the cam track 24 rocks the differential housing l8 tomomentarily increase the speed of the gear wheel 3|, between table speedand peripheral speed of the roll during forming of a merlon. The spacedrelation of the roll to the table and the rate of rotation of the rollare at all times such that the roll will not cause any change in theoriginal thicknes of the glass sheet, the glass being simply pressed orrolled to the contour of the table, and without any stretching orthickening of the glass at the bends or elsewhere.

In the operation of shaping a sheet of glass, the cradle 9 and the tableII carried thereby are movedto the left by operation of'the motor l2 inone direction, to the position shown in Fig. 3.

Thereupon,-a glass sheet 50 heated to a temperature of 1600 F. or othersuitable temperature at which it can be bent, is placed on an inclinedsupporting element 51 which is at approximately 45 inclination, so thatthe glass will slide down the same under gravity. The lower forward edgeof the glass is caused to engage a rib 52 on the table II, whereupon themotor i2 is caused to operate in the reverse-direction to move thecradle 8 toward and past the position shown in Fig. 1. During thismovement. the crimping roller 39 is constantly rotated at variablespeeds thus maintaining synchronism and is periodically slightly raisedand lowered, as above described. to cause the glass sheet to conform tothe contour of the table top. When the cradle has advanced far enough tomove the table from beneath the roll 39 and past the housing 32, themotor is stopped and the glass shap can be pushed laterally into anannealing lehr. it being understood that the glass has become cool(perhaps 1000" F. to 1200 F.) enough to permit such removal withoutdeformation. The glass sheet 50 may initially be formed in any suitablemanner, with or without the inclusion of reinforcing mesh therein andmay be -pre1iminarily trimmed tosize or not.

In forming structural elements, the sides of whose troughs are somewhatsteeply sloped as in the present instance; to form an economical shapewherein larger portions of the glass (as represented by the crenels 44and merlons 45) are farther from the neutral axis of bending, withconsequent greater structural strength than if the sides of the troughswere less steeply inclined, it i desirable to use a crimping rollerhaving no more than four ribs such as 46, since a greater number of ribswould tend to foul or stretch the glass before it reaches the place ofcontouring.

If the glass sheet is initially of substantially greater than 1600 F. or1650 F., it can be caused to sag into depressions such as 41 in a tabletop, without the necessity of being pressed therein by a. crimping roll.In such case, the table will be moved at variable rates of speed, sothat when the glass is sagging into the depressions 41, the table willbe moved more slowly than when the glass is settling upon the fiatbottoms of the depressions 41, and the speed of the table movement. willbe further slightly increased when the glass is being brought intoengagement with the rear walls of the depressions 41, so as to maintainthe glass at uniform thickness.

, The structural shape, as shown in Fig. 5, will have longitudinalflange portions 54 of desired width whereby it may be connected tostructural framework, it being understood that the ends of thechannel-like portions will be suitably sealed as is common in thebuilding art. These flanges 54 can be made of various widths to permitcutting away portions thereof to fit various spacings in structuralframework. When the shape is used in a skylight, it will be placed withthe edge portions 54 uppermost, so that rain will be directed away fromthe joints at such edges.

. Structural glass elements made as shown in Fig. 5 have greaterstrength by reason of the fact that the major portion of the glass ispresent in the crenels 44 and merlons 45, which are offset substantialdistances from the neutral axis of the bending stresses. For example,the distance between the opposite faces of the element may be five timesthe thickness of the glass sheet.

The plate can initially be formed while in a very plastic condition, bya rolling operation and simultaneously incorporating a wire meshtherein,

2,899,825 in the usual manner. Then while still in a somewhat plasticcondition, it can be pushed down the incline 51 to the table and givenits structural 'forming the flanges or depressed portions 54 (Fig. 5) atthe lower plane of the sheet as it is placed on the table, theseportions can engage the supporting surface to which the sheet is re-'-moved from the table, while still hot, and thereby held against sagging.

The bending of sheets in the manner described plastic, supporting theplate in an inclined posilon, placing the forward edge thereof on the Iforward edge of a table that has depressions extending crosswisethereof, and bringing the plate into parallelism with the table whilebending it to the contour of the depressions, successively.

5. The method of forming structuratshapes and the like of plastic sheetsthat are of a plasticity herein is of advantage not only becausethickening and thinning at the bends is avoided, but becausereinforcement mesh that may be incorporated therein will be maintainedat its proper depth or plane with respect to the sheet surfaces, andwithout serious disturbance ofthe intimate sufllcient to sag of theirown weight and are subsequentlyhardenable, which comprises supporting aplastic sheet in an inclined position, placing the forward edge thereofon the forward edge of a table that has depressions extending crosswisethereof, and bringing the sheet into parallelism with the table at suchrate that portions thereof will successively sag to the contour of thedepres sions.

s. The method of forming structural shapes I and the like of plasticsheets that are of a issengagement as between the reinforcement and theplastic sheet.

While the invention has herein been described as employed in the formingof structural glass, it will be understood that certain features thereofsuch as the shifting of the roll perpendicularly to the table and thechanging of roll speeds could advantageously be employed in connectionwith the shaping of other materials such as hot steel sheets, plasticclay and the like.

, I claim as my invention:

1. The method of forming structural glass and the like, which comprisestaking a glass plate which is at sufficiently high temperature to beplastic, first placing only the forward edge thereof upon a table. thathas depressed areas extending crosswise thereof, and bringing theremaining portions of the glass successively into engagement with thetable while bending the glass to the contour 'of the depressions, theglass being maintained atsuch temperature and deposited upon the tableat such rate as to avoid substantial changes in thickness of the plateas a result of the bends formed therein.

2. iihe method of forming structural glass and the like, which comprisestaking a glass plate which is at sufficiently high temperature to beplastic, placing the glass in an inclined plane relative to a table thathas depressed areas extending crosswise thereof, with the forward edgeof the glass on the table, bringing the remainder of the glass plategradually into engagement with the table, by. progressively moving italong theinclinecl plane and into approximate parallelism with thetable, therate'of movement and the plasticity of the glass being suchthat portions of the glass will assume the contours of the saiddepressed areas.

3. The method of forming structural glass and the like, which comprisestaking a glass plate which is at'suiliciently high temperature to beplastic, first placing only the forward edge of the glass upon a tablethat has depressed areas, moving the other portions of the plate 'to thetable, and pressing the glass into said areas, successively, at suchvariable speeds of progressive bending in each'area, relative to thesaid movement of the plate, that the thickness of the plate is notsubstantially changed as the result of the bending thereof.

4. The method of forming structural glass and the like, which comprisestaking a glass plate which is at suiliciently high temperature to beticity suflicient to sag of their own weight and are subsequentlyhardenable, which comprises supporting a plastic sheet in an inclinedposition, placing the forward edge thereof on the forward edge of atable that has depressions extending,

crosswise thereof, and bringing the sheet into parallelism with thetable at such variable rate that portions. thereof will sag to thecontour of the depressions, without substantial change in thick-v ness.

7. Themethod of forming. structural shapes and the like of plasticsheets that are subsequently hardenable, which comprises supporting asheet in an inclined position, with its forward edge on the forward edgeof a table that extends beneath the sheet and which has depressionsextending crosswise thereof, and bringing the sheet into parallelismwith the table, while bending it to the contour of the depressions,successively.

8. The method of forming structural shapes and the like of plasticsheets that are subsequently hardenable, which comprises supporting asheet in an inclined position, with its forward edge on the forward edgeof a table that extends beneath the sheet and which has depressionsextending crosswise thereof, and imparting forward movement to the tableand the sheet relative to the zone at which the sheet is supported, tobring the sheet into parallelism with the table, while bench ing it tothe contour of the depressions, successively.

9. The method which comprises plac ng a reinforcement mesh of flexiblematerial in a plastic sheet which is of subsequently hardenableinaterial, first placing only the forward edge of the reinforced sheeton the forward edge of a table that has depressed areas extendingcrosswise thereof, and bringing the remaining portions of the sheetagainst the table while successively bending portions thereof to thecontour of each depression in succession and, at such rate as to avoidsubstantial changes in the thickness of the sheet.

10. The method of forming structural shapes and the like of plasticsheets which are of a plasticity sufllcient to be bent and aresubsequently hardenable, which comprises placing a portion of a plasticsheet on a table that has depressed areas extending crosswise thereof,and with the sheet engaging a single raised area of the table, thatdefines one side of a depressed area, and bringing remaining portions ofthe sheet progressively into engagement with other raised areas. insequence while bending it to the contours of the depressed areas,successively.

11. The method of forming structural shapes and the like of plasticsheets which are 01 a plasticity sufllcient to be bent and aresubsequently hardenable, which comprises imbedding areinforcement'material in a sheet, placing a portion of the sheet in a,plastic condition on a table that has depressed areas extendingcrosswise thereof, and with the sheet engaging a single raised area.

' of the table, that defines one side of a depressed area, and bringingremaining portions of the sheet progressively into engagement with otherraised areas, in sequence while bending it to the contours of thedepressed areas, successively.

12. The method of forming structural shapes and the like 01 plasticsheets that are of a plasticity sufllcient to be bent and aresubsequently hardenable, which comprises placing the forward edgethereof in a depression of a. table that has depressions and raisedareas extending crosswise thereof, bringing the remaining portions ofthe sheet progressively into engagement with the table while bending itto the contour of the depressions, in sequence, the sheet beingdepressed also at its rear edge, and shifting the formed sheetlaterally, to remove it from the table.

FRANK W. PRESTON.

